From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936664AbdEWJmO (ORCPT ); Tue, 23 May 2017 05:42:14 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:41741 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932938AbdEWJmL (ORCPT ); Tue, 23 May 2017 05:42:11 -0400 X-AuditID: b6c32a35-f79806d000002bf4-22-592403e70706 MIME-version: 1.0 Content-transfer-encoding: 8BIT Content-type: text/plain; charset="UTF-8" Message-id: <592403E7.8060906@samsung.com> Date: Tue, 23 May 2017 18:41:59 +0900 From: Chanwoo Choi Organization: Samsung Electronics User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 To: Arvind Yadav , myungjoo.ham@samsung.com, kyungmin.park@samsung.com, krzk@kernel.org, kgene@kernel.org, javier@osg.samsung.com Cc: linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1] PM / devfreq: exynos-ppmu : Handle return value of clk_prepare_enable In-reply-to: <1495191364-16015-1-git-send-email-arvind.yadav.cs@gmail.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrGJsWRmVeSWpSXmKPExsWy7bCmnu5zZpVIg+ePzSyu9S5ktnjzdg2T Rf/j18wW589vYLc42/SG3WLT42usFpd3zWGz+Nx7hNFixvl9TBa3G1ewOXB57Jx1l91j06pO No/NS+o9tvQDeX1bVjF6fN4kF8AWlWqTkZqYklqkkJqXnJ+SmZduq+QdHO8cb2pmYKhraGlh rqSQl5ibaqvk4hOg65aZA3SZkkJZYk4pUCggsbhYSd/Opii/tCRVISO/uMRWKdrQ0EjP0MBc z8jISM/EONbKyBSoJCE1Y/OxH0wFq7kqjs5vYW5g3MbRxcjBISFgIvH9j3QXIyeQKSZx4d56 NhBbSGAHo8Sefp8uRi4g+zOjRMe+/4wQRSYS0z/cZIVIABU9/N7PDpLgFRCU+DH5HgvIUGYB eYkjl7JBwswCmhJbd69nh6i/xyjRtfkHE0S9lsTBb0dZQepZBFQlXs92BQmzAYX3v7gBdgS/ gKLE1R+PwfaKCkRI7Jz/DWyOiMACRonVC5rAjmAWaGWUeNq9CaxDWCBeYvu+DhYQm1PAS2L1 keVgRRICx9glXn1tZoZ4WVZi0wFmiG9cJE73b2CFsIUlXh3fwg5hS0k0vnzIBNHbziixeQ7I ZyBOB6PE/ZWNUB3GEqe6Gpkg/uSTePe1hxViAa9ER5sQRImHxOLWf2wQtqPE563XmCFBMZdR ovHhY8YJjAqzkEJvFiL0ZiGF3gJG5lWMYqkFxbnpqcWGBYZ6xYm5xaV56XrJ+bmbGMFpVMt0 B+OUcz6HGAU4GJV4eDUeK0UKsSaWFVfmHmKU4GBWEuE9/F05Uog3JbGyKrUoP76oNCe1+BCj KTDwJzJLiSbnA1N8Xkm8oYmlgYmZETDZWRoaKonziq6/FiEkkJ5YkpqdmlqQWgTTx8TBKdXA aHfhTmGap9PHLg1rvpS7nyU8D66KevX3gY7PVLeFPg5OWSv4ub0ueh9b0JAoWz8nbeH5/X1V R6JWf11wvfjXUs3Jhh57zd/lXNjAmHgugyEpYMvOYyYSk5iTmY9cXCA+vTvuMJvsVJ+PpwO6 np2ba67fu2TjisPRDof3fFyy4U8534KzS9aeKFViKc5INNRiLipOBABPcfsAuQMAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrCIsWRmVeSWpSXmKPExsVy+t9jAd3nzCqRBlefqlpc613IbPHm7Rom i/7Hr5ktzp/fwG5xtukNu8Wmx9dYLS7vmsNm8bn3CKPFjPP7mCxuN65gc+Dy2DnrLrvHplWd bB6bl9R7bOkH8vq2rGL0+LxJLoAtys0mIzUxJbVIITUvOT8lMy/dVik0xE3XQkkhLzE31VYp Qtc3JEhJoSwxpxTIMzJAAw7OAe7BSvp2CW4Zm4/9YCpYzVVxdH4LcwPjNo4uRk4OCQETiekf brJC2GISF+6tZwOxhQS2MUocfh8EYvMKCEr8mHyPpYuRg4NZQF7iyKVskDCzgLrEpHmLmLsY uYDKHzBKXPo5gRGiXkvi4LejrCD1LAKqEq9nu4KE2YDC+1/cABvPL6AocfXHY0aQElGBCInu E5UgY0QEFjBKvLu4gxHEYRZoZZSY3LgQrEFYIF5i+74OFohl8xkl7j35zASS4BTwklh9ZDnr BEbBWUhunYVw6ywkty5gZF7FyJVaUJybnltsVGC4iREYg9sOa/nvYPxxNvoQowAHoxIP74pg 5Ugh1sSy4srcQ4wSHMxKIryHvwOFeFMSK6tSi/Lji0pzUosPMZoCvTeRWUo0OR+YHvJK4g1N LI1MDMzMDI0MjM2UxHknBH6JEBJITyxJzU5NLUgtgulj4uCUamCseXj2PZt18sXgzUFc/WpX vi0ul6h2F57+e9oeabVux5mf1rpV3RZtP+dj5JvEwjm/Nl7z3eWYCcySxgu+pqal5FwSNYoI SpjLsZkj8KqWaPVBsRn8x0sfLC/5Ehs1Y9PUyXXvtrgwtQkkLjolqTjV0fflmcr1Z/+8Do9f YuXHnvfSIOXl3VolluKMREMt5qLiRACIl4pC1wIAAA== X-MTR: 20000000000000000@CPGS X-CMS-MailID: 20170523094159epcas1p3d48ec6dbd7105f9b9e663ba4ad9e8845 X-Msg-Generator: CA X-Sender-IP: 182.195.42.79 X-Local-Sender: =?UTF-8?B?7LWc7LCs7JqwG1RpemVuIFBsYXRmb3JtIExhYihTL1fshLw=?= =?UTF-8?B?7YSwKRvsgrzshLHsoITsnpAbU2VuaW9yIEVuZ2luZWVy?= X-Global-Sender: =?UTF-8?B?Q2hhbndvbyBDaG9pG1RpemVuIFBsYXRmb3JtIExhYi4bU2Ft?= =?UTF-8?B?c3VuZyBFbGVjdHJvbmljcxtTZW5pb3IgRW5naW5lZXI=?= X-Sender-Code: =?UTF-8?B?QzEwG1RFTEUbQzEwVjgxMTE=?= CMS-TYPE: 101P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20170519105745epcas5p29a5cbb259cd15138d7220f34e130e00a X-RootMTR: 20170519105745epcas5p29a5cbb259cd15138d7220f34e130e00a References: <1495191364-16015-1-git-send-email-arvind.yadav.cs@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017년 05월 19일 19:56, Arvind Yadav wrote: > clk_prepare_enable() can fail here and we must check its return value. > > Signed-off-by: Arvind Yadav > --- > drivers/devfreq/event/exynos-ppmu.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/devfreq/event/exynos-ppmu.c b/drivers/devfreq/event/exynos-ppmu.c > index 9b73509..8f6537a 100644 > --- a/drivers/devfreq/event/exynos-ppmu.c > +++ b/drivers/devfreq/event/exynos-ppmu.c > @@ -648,7 +648,11 @@ static int exynos_ppmu_probe(struct platform_device *pdev) > dev_name(&pdev->dev), desc[i].name); > } > > - clk_prepare_enable(info->ppmu.clk); > + ret = clk_prepare_enable(info->ppmu.clk); > + if (ret) { > + dev_err(&pdev->dev, "failed to prepare ppmu clock\n"); > + return ret; > + } You're right. But, actually, some ppmu device-tree node doesn't include the clock information because exynos clk driver don't support the clock for some ppmu devices. Until now, the clock of ppmu devices are default on state. Before applying this patch, exynos clock driver have to support the ppmu's clock and then add the clock information to the device tree of ppmu devices. > > return 0; > } > -- Best Regards, Chanwoo Choi Samsung Electronics